Any such mutation and subsequent pandemic would lead to delays of up to 17 weeks in burying or cremating victims, the document - said to have been discussed by a cabinet committee - states.

And the document warns the prospect of "common burial" would stir up images of the mass pits used to bury victims of the Great Plague in 1665.

However, it "might involve a large number of coffins buried in the same place at the same time, in such a way that allowed for individual graves to be marked".

The report suggests town halls could deal with what it refers to as a "base case" of 48,000 deaths in England and Wales in a 15-week pandemic.

'Strong plans'

Entitled Managing Excess Deaths in an Influenza Pandemic and dated 22 March, according to the Sunday Times the document says vaccines would not be available at least for "the first wave" of a pandemic and would not be a "silver bullet".

The newspaper claimed ministers discussed the issue last week and, although they were alarmed at the prospect of such delays to burials, accepted there might be no option in the event of a mass outbreak.

Bird flu has already prompted the slaughter of millions of birds across three continents since the H5N1 strain emerged three years ago.

And it has claimed the lives of more than 100 humans - all of whom had been in close contact with infected birds.

Chief Medical Officer Sir Liam Donaldson has said preparing for a pandemic was "a top priority" and "strong plans" were in place to respond.

These plans include building a stockpile of 14.6 million doses of anti-viral drugs to treat those who fall ill during a pandemic.